Jeff 'Swampy' Marsh
Acting
Jeff "Swampy" Marsh (born December 9, 1960) is an American animator, writer, director, producer, and voice actor associated with several animated television series, most notably as an executive producer and the voice of Major Monogram for Disney's animated series Phineas and Ferb and Milo Murphy's Law, both of which he co-created with Dan Povenmire. Marsh was born in Santa Monica, California, where he grew up with a heavily blended family dynamic. Marsh has been and continues to be a driving force behind several animation projects, working for over six seasons on the animated television series The Simpsons. Marsh continued to work on other animated television series, including King of the Hill and Rocko's Modern Life, before moving to England in 1996.
Known for
Acting22
tvAgent P Under C
2026
Major Monogram (voice)
movieSpiked
2025
Big Boss Croc / Exterminator (voice)
tvHow Not to Draw
2022
Major Monogram (voice)
moviePhineas and Ferb the Movie: Candace Against the Universe
2020
Major Monogram (voice)
tvMilo Murphy's Law
2016
Additional Voices (voice)
movieO.W.C.A. Files
2015
Major Monogram / Additional Voices (voice)
moviePhineas and Ferb: Last Day of Summer
2015
Major Monogram (voice)
moviePhineas and Ferb: Night of the Living Pharmacists
2014
Major Francis Monogram (voice)
moviePhineas and Ferb: Star Wars
2014
Major Hologram / Imperial Officer Jeff / Additional Voices
moviePhineas and Ferb Save Summer
2014
Major Francis Monogram / Additional Voices (voice)
moviePhineas and Ferb: Mission Marvel
2013
Francis Major Monogram / Gordon Gutsofanemu / Additional Voices
moviePhineas and Ferb: The Perry Files - Animal Agents
2013
Major Monogram (voice)
moviePhineas and Ferb The Movie: Across the 2nd Dimension
2011
Major Francis Monogram / Monogram-2 (voice)
moviePhineas and Ferb: Summer Belongs to You!
2010
Major Francis Monogram / Additional Voices (voice)
moviePhineas and Ferb Christmas Vacation!
2009
Major Monogram (voice)
tvPhineas and Ferb
2007
Francis Monogram (voice)
tvBounty Hamster
2003
(voice)
tvAaagh! It's the Mr. Hell Show!
2001
Josh (voice)
movieUntitled Phineas and Ferb Movie
Major Francis Monogram (voice)
Production11
tvHey A.J.!
2026
Executive Producer
tvSuper Happy Magic Forest
2024
Executive Producer
moviePhineas and Ferb the Movie: Candace Against the Universe
2020
Executive Producer
tvMilo Murphy's Law
2016
Executive Producer
movieO.W.C.A. Files
2015
Executive Producer
moviePhineas and Ferb The Movie: Across the 2nd Dimension
2011
Executive Producer
tvTake Two with Phineas and Ferb
2010
Executive Producer
tvPhineas and Ferb
2007
Executive Producer
movieLooks Can Kill
1994
Associate Producer
movieUntitled Phineas and Ferb Movie
Executive Producer
Writing8
tvPete the Cat
2017
Writer
tvPhineas and Ferb
2007
Writer, Story
Creator5
Crew3
moviePhineas and Ferb The Movie: Across the 2nd Dimension
2011
Sequence Supervisor
moviePhineas and Ferb: Summer Belongs to You!
2010
Additional Writing
tvRocko's Modern Life
1993
Additional Writing
Directing3
Art1
tvRocko's Modern Life
1993
Storyboard Artist